The present invention relates to a multi-contact socket which has a relatively large number of contacts, and more particularly, to a multi-contact socket which has an electromagnetic shield.
FIG. 1 is a diagram showing, partly in section, the construction of a conventional multi-contact socket disclosed in U.S. Pat. No. 4,810,210, for example. A square body 10 made of an insulating material has a plurality of contact housing holes 12 arranged in a matrix form, in which a plurality of socket contacts 14 are housed. The rear half portion of the body 10 has a hollow 13, which is open at its rear end but bottomed with a terminal holder 20. A terminal of each socket contact 14 is bent down at right angles in the hollow portion 13 and projects out of the body 10 through the corresponding one of holes 25 made in the holder 20. The body 10 is covered over its top, both sides and underside, except the holder 20, with a square tubular metal shield cover 30, which is, in turn, covered, except the holder 20, with a square tubular case 53 of an insulating material. In the front half portion of the socket there is formed a square groove between the case 53 and the shield cover 30, for receiving the front end portion of a square tubular metal cover 70 of the mating plug.
The multi-contact socket shown in FIG. 1 is mounted on a printed circuit board (not shown) with fitting legs 43 of the cover 30 and the terminals 15 inserted in through holes of the printed circuit board and with the front marginal portion of the socket received in a hole 61 made in a metal side wall 60 forming a part of an electronic equipment housing. When the mating multi-contact plug disclosed in the aforementioned United States patent is connected to the above multi-contact socket, the front portion of a square tubular metal cover 70 of the plug is inserted into the groove 51 of the multi-contact socket from the outside of the electronic equipment housing, i.e. from the left-hand side of the side wall 60 in FIG. 1. In such a state the top, bottom and both side panels of the shield cover 30 overlap and make direct contact with the corresponding panels of the metal cover 70 of the mating plug, but since the metal cover 70 inserted in the groove 51 is received inside the socket case 53, neither the shield cover 30 nor the metal cover 70 makes direct contact with the side wall 60 of the electronic equipment housing, and since the side wall 60 has a window for electromagnetic noise of a size corresponding to the thickness D of the wall of the case 53, electromagnetic shielding is incomplete between the inside and outside of the side wall 60 of the housing. The conventional multi-contact socket, when thus mounted on electronic equipment, is defective in that shielding of the electronic equipment against electromagnetic interference is not satisfactory.